1. Field of the Invention
The present invention generally relates to press switches, and more particularly to a press switch having a force-to-detach function for assuring the safety of a use of electric appliances such as the use of a tool machine.
2. Description of the Related Art
A switch provided for electric connection has been used for years, and switches are a necessary device for controlling power supply. With the installation of a switch, we can disconnect a power supply as needed to prevent any accident caused by a continual use of power supply. The constantly connected power always keeps the power on and disconnects the power when the power is not needed. Therefore, all electric appliances and products require switches, and the basic operating principle of a switch is to electrically connect two electrodes to form a circuit for accessing electric power. If the two electrodes are not connected, the power will be disconnected, and thus the electric power cannot be accessed.
In general, a switch makes sure the connection and disconnection of electric power, and also takes safety into consideration. For example, electric leakages and wrong connections should be prevented. Tool machines such as electric drills, electric saws, or electric grinders involve a certain risk for their operations, and thus these machines adopt the constantly disconnected power. In other words, if the machines are not in use, their power is kept disconnected all the time. Such an arrangement assures that the machine is not operable without electric power supply when they are not in use and assures the safety of the operators. However, the tool machine produces a high temperature due to the high current or repeated contacts, and the two contact points may be melted or become a sticky status, and thus causing a short circuit to the tool machines. Since most constantly disconnected power measures use a single point for the electric contact, therefore the sticky contact terminals cannot be detached from each other, and it will jeopardize the safety of users. Therefore, finding a way of improving the press switch structure having a force-to-detach function and solving the problem of a short circuit of the tool machines caused by the sticky contacts, the high current, or repeated contact under a high temperature of operation demands immediate attentions and feasible solutions.